Master's thesis: Climate positive hydrogen production via biomethane pyrolysis using liquid metal catalysis approach.

Many industries, including the iron and steel, chemical, and refineries, need climate- and energy-efficient hydrogen production for their green transition. Hydrogen production via (bio)methane pyrolysis (MP) has recently attracted great interest. The process involves the decomposition of methane (CH4) in an oxygen-free environment into hydrogen gas (H2) and solid carbon (Cs) according to the following reaction.

CH4(g) → 2H2(g) + Cs, ∆H° = +74 kJ/mol

This results in a CO2-free production. The solid carbon enables simplified storage ((BE)CCS). Alternatively, the carbon product can replace existing materials, e.g. carbon black, which its production today results in a large CO2 emission. Compared to water (H2O) electrolysis,

H2O(l) → ½O2(g) + H2(g). ∆H° = +286 kJ/mol

only 13% of the energy is theoretically needed to produce 1 mol of H2 which is one of the biggest advantages with the MP technology. MP can be divided into two categories, catalytic-, and non-catalytic. In catalytic MP, the goal is to lower the activation energy of the CH4 reaction mechanism to reach a high selectivity of H2 and Cs at moderate reactor temperatures (<1000°C). Catalysts based on transition metals can decompose CH4 at temperatures as low as 500 to 600°C, however, they are susceptible to rapid deactivation due to Cs depositions. To overcome this issue, molten metal catalysts have been developed that allow for high CH4 conversion (95 %) at a temperature of 1065 ℃ without the production of intermediate species while the produced Cs can be easily removed and collected since the Cs floats on the surface of liquid catalyst [Science 358 (2017) 917-921]. Recent development of a ternary NiMo-Bi liquid alloy catalyst has lowered the reaction temperature down to 800 °C with 100% H2 selectivity and 80% CH4 conversion efficiency [Science 381 (2023) 857-861].

MSc thesis project
LTU together with RISE in Piteå are currently building up competence in MP and we think it is an appropriate area for students interested in contributing to renewable production of hydrogen. Currently a laboratory scale reactor is under construction at RISE ETC in Piteå. The MSc Thesis project are suitable for 2 students working together in the following as describe below.

Experimental work with laboratory reactor where the main aim is to investigate the yield of hydrogen production as a function of different process parameters in the reactor (temperature, residence time, input gas composition) for different kinds of liquid metal catalysts. After the experiments the catalysts and the produced carbon will be characterized with respect to morphology and chemical composition. Based on the experimental values an energy analysis/technoeconomic analysis of a MP plant will also be performed.

Competence of the MSc thesis candidates
Background in energy technology or chemical engineering.

Terms
Scope: 30 hp, one semester full time, with flexible starting date.
Location: Piteå

Welcome with your application!
For questions and further information regarding this project opportunity contact recruiting manager Christopher Muller at christopher.mueller@ri.se. Last application date: 31st of October.